US1874887A - Can making and apparatus - Google Patents

Description

Aug. 3Q, 1932. I w, BURNS 1,874,887

CAN MAKING AND APPARATUS Filed Jan. 27, 1928, 2 Sheets-Sheet 1 INVENTOR.

ATTORNEYS.

Aug. 30, 1932. w BURNS 1,874,887 I cm MAKING- AND APPARATUS- ATT RNEYS.

Patented Aug. 30, 1932 UNITED STA ES- ATENT OFFICE;

WILFOR-D n'nuims, or BURLINGAME, cALIroRNImAssIGNoRfrom. .1. 13.00;, or SAN Y FRANCISCO, CALIFORNIA, A CORPORATION or DELAWARE V CAN MAxI G nn APPARATUS l Application filed January 27, 1922;. Serial No. 250,030.

This invention refers to can making and the type of so-called tin can wherein a circumferential tearing strip is provided for releasing one end of the can, and particularly to such a can as shown in my issued Patent #1,615,930' and copending application filed under Ser. No. 173,460 whereinthe tearing strip is defined by score lines on the outer layer of a triple layer of metal extending as a band around the can adjacent one end thereof. 7 y

' The objectsof the invention are to provide an improved method of folding the can blank to form the triple layer, and toa method of preventing the solder used on the body joint from spreading excessively between the layers forming the band with consequent soldering of the layers together so that the tearing stripishard toremove, or to prevent anyobjectional spreading of the solder at any point on a can whether formed with a triple layer band of metal as described or not, alsoto a can made by my method, and to the apparatus for making the same. I

Since a can with the triple layer band and tearing strip has'been describedin'detail in my Patent #1,615,930- and my copending case, and the description is lengthy, the present application will be much shortened by re-. ferring to said patent and copendingcase for a fuller description of the can,-,a ndespecially to the figures of the drawings ofboth cases showing, first the flat can blank, second the blank foldedtojform the triple layer, and third the folded blank formed into thetubular can body withvertical body seam locked. In the drawings accompanying the present application Figs. 1, 2, 3 and 4 are end edge views of the sheettin can blank as successively folded in accordance withmy method to produce the triple layer band mentioned.-

Fig. 5 is a portion of Fig. 7 of my copending case hearing same reference figures for identification therewith and shows in elevation the body of the can at the vertical joint. Fig. 6 is a perspective view of the same part of the can shown in Fig; 5 with the upper corners of the outer layer of metal bent downward to expose the joint within the triple layer portion.

apparatus for folding the blank to formthe triple layer" band and for inserting antisolde'r' spreading meansat' a point on the metal so as to ultimately come between the folds of'the band. f

Fig. 8 is a side elevation of Fig. -7, an Fig. 9 is a plan view of portion of the apparatus'of Figs. 8 and 9. Y In the manufacture of a can of the ter, described considerable difficulty has been met both in forming the triple layer of metal rapidly and accurately on automatic machinery, and also in preventing the layers of tin from soldering together over anarea extending laterally from the verticalseam of the can, which efiect sometimes makes it diflicult to tear ofithe scored tearing strip.

After "considerable experimentation with various folding steps and continuous progressive folding of the blankthrough suitable forrning guides and rollers to form the triplelayer I have evolve'da method comprising four stages which may be carried out charac- Fig. 7 is an end elevation and sectionof '7 Ihave experimented with various substancesapplied atthe'point mentioned, such for instance as paint, varnish, printingink,

'etc yand while several" of thesewere quite effective, I found the best results were obtained by gumming or otherwise inserting a small paper patch at such points between the layers where solder was objectional. The paper used is thin and does not" interfere with the, usual automatic operations on the body machine preparatory'to passage of the formed bodyover the soldering horn.

Since the usual operationsof tin can making and the machines used therefor are well understood by those versed in the-art, no

needlessexplan'ation of such machines or.

operations will be attempted" herein, butit twill sufli'ce to say that prior toreaching the body machine wherein the can blanks are intermittently advanced and stopped at succeeding stages for folding the lock seam, forming the body, locking, and closing the seam, I advance the died-out and scored blanks ;v through means of a standard body machine feed; intermittently along a guide (which may be an extension of the body machine guide or a separate machine feeding into the bodymachine') and stop the blanks" at stages along the guide for successively bending or folding one long margin of the blank to the positions shoWninFigs. 1,2, 3 and 4.

In F 7 a representative portion of the machine used for carrying out the operati'onsis shown and in which 21 is a main powstage.

er, or cam shaft from which all moving parts are positively driven by any of the well known means not-shown so that all operations will register with the blanks as they are intermittently advanced from stage to This shaft 21 is rotatably .mounted on vframe members 22 suitably spaced-alongthe machine, and supported on these frame members is a guide 23 along which the can blanks 1' are intermittently advanced from stage to stage through means of anysuitable type of intermittent feeding mechanism such as the spring hooks or paw-ls 24 mounted onthe bar 2-5 reciprocated ther'eqnired distance of travel by any suitable transmission connections to-the shaft 21, as well understood in the art, and therefore not shown .on the drawings. r I s .At the different stages representedby Figs l, 2, 3, 4 the mar-gin of themetal sheet or blank 1 passes between suitablyshaped aws as at 26 27 for stage 1 between which it is; clamped while brake jaw 28 moved by cam or crank CORIIQOUOIHQQ to the shaft 21' folds the margin to form one of the steps offorming the triple layer bandw-hich, will extend around the completed can body.

. in'th-is apparatus the blank is clamped by slight downward movement of which carries the upper jaW' 27; the movement being effected by any suitable-cam connection to shaft 21 indicated at .33 and therefore timed With the feed and brake movements.

' Brake jaw 28 is ihere shown as sliding though it is understood that at this stage or wa t any of the other stages. the folding-jaw' may be pivoted like any common sheetmetal brake, whichever arrangement best serves the layout offthe machine or angle to; which the sheet islto be bent.v

The first stage operation described results in an upward right angle fold of the margin fa-s shown at A in Fig. l, and after which the sheet is advanced and. stopped atv stage .2 whe'reat a similar arrangement .of elements folds the upstanding wall downward. and

outward at an; angle of substantially dethe can is complete.

grees as at B in Fig. 2, after which the blank passes to stage 3 where the bends are closed in a direction toward the flat sheet of the body to about 30degrees as at C in Fig. 3, and at the last stage the folds are flattened down against the main body of the sheet so as to form with it a triple layer. of metal the length of the blank with the score lines D, E for the" tearing strip positioned on the under sidefof the outer sheet at points shown in Fig. Also that the tearing strip will eventually be on'theouter layer of the'band when In dieing out the'can blank it isformed to provide afreely projecting tongue 5 extending in line with the tearingstrip score lines .1), E adapted forengagement with a key for winding or tearing of]? the tearing strip in the common manner and one of the presentimprovemen-tsr consists of outwardly offsetting thistongue from the point .31 in Figs. .5 and 6 about za thirty-second of an inch thereby preentihg capillary attraction of the solder under thetongue at the time. of soldering which otherwise spreads the solder to the right of .4 ofmetal bent down at the body joint 57 showing one of my paper patches 2' in position so as to be' under the rear end of the -;tearing strip.

This patch 2 is preferablyapplied at stage .lIof the margin folding operations by the mechanism shown in Figs. 7., 8 and 9 and .\'vh.erein a reciprocating'punch 32 cuts out a .patgih'of gummed paper from a tape ll and forces it'against the upturned margin as soon as theibrake jawQSYfaIl'ssuificiently to clear the punch. -lhis punch is of a shape to cut but the form of patch desiredand is mounted on a"s1idab le carriage 34 reciprocated in proper time with t'h'ebral're jaw 28 by means of an osci'l'lary crank arm 35 which normally is forced forward a spring 36 and backward by a cam 37 on the main shaft 21. The

cam holds the punch withdrawn and clear of the brake jaw unti l'thejaw has formed the right angle bend to the can blank and fallen to clear the punch and at which time the cam 37 falls away to permit spring 36 to force the punch forward Thspunch operates through a die'plate 38 and the punch is hollow and carries a centering point 39 resiliently forced forward bya light spring 40. i 1' v -shape and setting ofthe cam being such that The gummed paper strip or tape 41 is car-' ried on a supply roll 42 from which it is led over a moistening roll 43, given a quarter turn and passed over idler 44 and behind the die plate, thence over a similar idler 44' and back between a pair of intermittent feed rollers 4546 which advance the paper strip at each return stroke of the punc The advancing rollers are actuated by a pin 47 projecting from the punch carriage 34 and engaging ratchet teeth 48 on one of the rolls. A spring pawl 49 is provided to prevent reversal of the rolls.

The paper supply roll 42 is carried in a receptacle 50 and which receptacle is provided with smooth disks 51 which may be adj usted against the sides of the roll to develop a proper working friction and which disks also overcome any necessity. of finishing the inner side walls of the receptacle.

The moistening roll 43 idles in a water trough 52 and a small idler 53 lies freely on top of the paper as it passes over the moistening roll.

whereby ried out.

I claim:

A sheet metal can body blank having a. fold formed by-overlapped contacting layers of metal, the opposite endsof the blank being designed subsequently to be joined to gether in a soldering seam; said fold including a tearingstrip in the outer layer thereof and a paper insert applied between the layers of the fold at a point adjacent one end of the blank to prevent objectionable spreading of solder along the tail end of the tearing strip when the ends of the blank are joined in the seam and to limit the soldering area along the strip to insure subsequent easy removal thereof.

- WILFORD E. BURNS.

the combined method'steps are car Gummed paper is preferably used for the paperstrip, though it should be noted that the folding operations at stages 1, 2, 3, 4 follow so quickly that some grades of ungummed paper simply moistened with water will stick sufliciently so that the patch will remain in place long enough to be folded into place between the layers of tin, and after which it will not shift.

Also is should be noted that if desired the paper may be omitted and the end of a plain punch inked so as to impress an ink spot on the sheet at the point desired, but I prefer the paper as it forms a more efiective solder barrier than any ink, paint or varnish which I have tried.

A trip is provided to prevent the punch working in case no blanks are passing through the machine and which includes a depending lever 54 normally riding on the blanks as they come along and formed to overlap the space between the blanks (about an inch). This lever is secured to a horizontal shaft 55 which carries a dog 56 in line to swing into a groove 57 formed in the sliding punch carriage when the same is drawn all the way back by the cam 37 If no blank is in place to support the trip lever 54 it will fall and the dog 56 will lock the carriage in inoperative position until a blank comes along and lifts the lever.

Having thus described my improvements in can manufacture it will be seen to comprise the insertion of a solder barrier between certain layers of tin, and a method of folding the metal in stages permitting of applying the solder barrier, also a can incorporatingthe novel features claimed whereby the tearing strip is provided with a limited soldered area so that its subsequent free removal is assured, and finally the special apparatus ioo

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